There are so many publications out there these days--both print and online--that one-time publication for anyone who writes, and I mean anyone, is inevitable . . .
But what do you need to do to make a living at it?
(1) Do good work, and FAST. To succeed, you have to promote the "draft early, revise often" approach. And by revise often, I mean to say that it's done with a short window of time . . . every day.
(2) Do a lot of work, all the time. There is simply no day off for the full-time writer. I've just sent copyedited review notes for one book to a publisher while I await the second round of proofs from yet another. Two of my contracted titles are in production right now--one due September 2008; one, September 2009. It's a labor of love and it's what I do, but outsiders simply have no idea how many other magazine, newspaper, and online pieces I write a week, month, and year. How many? A Sunday newspaper column per week, every week (going on 11 years for my "current" market). Two to three article posts for one website a week, plus two a month for another--both gigs are contracted; I enjoy writing for both anchor clients. Then there are the national print magazine features here, and another one there (maybe a regional), around three-dozen annually. There's other stuff too . . . I say yes to almost everything (another secret: find a way to make it work, whether the writing job is for $50 or $1,500).
(3) Do other things related to your central activity. My college classes (adjunct work all of it, and last I checked the university system referred to me as a "temporary instructional staffer," though I've taught for them since '91), and seminars (outdoor shows, library events, etc.). Both help to pay the bills too. As does selling my photos with articles . . .
(4) Develop a wide range of markets: local, regional, national, and international. I've written regularly (or sporadically) for several hundred different regional and national outdoor, sporting, and even literary publications over the past quarter century (seriously). This includes poems, fiction, nonfiction, posts on the Boston Celtics, online how-to pieces, destination sidebars, 2,000 to even 6,000-word magazine features on wild turkeys, newspaper columns, outdoor book contributions, editing jobs, narratives for two films, lyrical essays, four commercial titles on fly-fishing, wild turkeys and the Pittsburgh Steelers, plus two skinny university press-run literary efforts, and I even a co-authored song, you name it.
(5) Love. Your. Craft. There's simply no other way around this one. If you love to write (I do), the rest of it--including regular publication--will follow. Laugh if you want, but I can't tell you how many people I've met who say they want to be writers, but for whom act of writing gets in the way. Go figure. It's absolutely the best lifestyle for me, but likely not for everyone.
P.S. These two books have not let me rest over the past six months, but you know what's funny: I miss the steady effort required to put one (not to mention two) together. Got it?